Ivan, Mircea, and Ioan Raşa. “A Voronovskaya-Type Theorem”. Rev. Anal. Numér. Théor. Approx. 30, no. 1 (February 1, 2001): 47–54. Accessed April 26, 2024. https://ictp.acad.ro/jnaat/journal/article/view/2001-vol30-no1-art6.